The overall objectives of the project are to examine the role that proteases and other acid hydrolases play in the turnover of proteins during synchronous vegetative growth; gametic differentiation and dedifferentiation in the unicellular eukaryote Chlamydomonas reinhardtii. Emphasis will be placed on studies with isolated and purified Cathepsin D, Cathepsin B and Leucyl arylamidase. Lysosomal-lie vesicles will be isolated and their hydrolytic enzyme content assayed.